Wednesday, November 3, 2010

Dividing Decimal Numbers

Question # 4 a) in your textbook : Without using a calculator, place the decimal point in the correct position. Show your thinking.

36.72 ÷ 30 = 1224

Showing my thinking: Use front end estimation. ( taking the first digit)
Step 1: 36.72 will turn into 30.
Step 2: 30 will stay the same. So it will be 30 ÷ 30, 30÷30 = 1
Step 3: Now you know that the answer be approximately 1

Answer: 36.72 ÷ 30 = 1.224


Question # 6 b) in your textbook: Estimate then calculate the answer.

4.56 ÷ 0.8 = ______

Estimation:
Step 1: Round 4.56 to the nearest whole number, which is 5.
Step 2: Change 0.8 to 0.5
Step 3: 5 ÷ 0.5 = 10

Answer: 4.56 ÷ 0.8 = 5.7


Question # 12 in your textbook: A contractor charged $398.75 to move the gravel for a garden. The contractor charges $72.50 per hour. How long did she work? Estimate, then calculate the answer.

Estimation:
Step 1 : Change $ 398.75 to $350.00
Step 2 : Change $ 72.50 into $ 70.00
Step 3 : 350 ÷ 70 = 5. That means the contractor worked for about 5 hours.

Answer: 398.75 ÷ 72.50 = 5.5 , the contractor worked for 5 and half hours.


If you need help on multiplication check this link out.


16 comments:

ghelo8-14 said...

GREAT JOB MARY !!!! YOU COULD HAVE ADDED A VIDEO PLUS A PIC SO PEOPLE WOULD BE MORE ATTRACTED TO THIS POST. AMAZING JOB MARY n_n

John816 said...
This comment has been removed by the author.
John816 said...

Good job Mary next time add video to help and its nice that you put the link, anyways good job.

Jackie8-16 said...

GOOD JOB MARYY! I like how you explained your estimations it was very clear. I think you should add a video or a picture to help your scribe out. (: I liked how you made the important things stand out (:

Janessa814 said...

Good job Mary but I think you should have added a little more color and maybe a video , but I like the way you explained things ! But good job still : D

joshL814 said...

I like your explanation. It's really clear. It could have been better if you put a video and a picture. Good Job though!

oudorn817 said...

Nice job! I like how you rounded the numbers to the nearest whole to make is easier . Next you should try adding a video because it's kind of boring just reading all the time.

Patricia817 said...

Good job Mary! The steps really helps. I like the game its really fun and it helps you learn multiplication. You might want to put a video and image to make it even better! anyways great job on your post!

Ian814 said...

Good job but you might wanted to put a picture and a video. But anyways good job

Aicelle817 said...

Good job mary ! I like how you showed the steps, but you might want to add a video or maybe a picture. Anyways great post ! And by the way i like the link.

norien873 said...

Great job! I like how you explained the answers it really made sense! I also liked the link that you added I tried it and it was fun! You could have put a video or a picture though.

CarloS8-16 said...

Goodjob! I like how you explained how to used front end estimation it really make sense and the link really help me alot because i can practice my multiplication.

daphne906 said...

Nice Job Mary! I like your explination, but next time you should add a video or maybe an image so we can understand it better, but for the rest of them,awesome job!

samantha873 said...

I liked your explanations but I think you should have added pictures or a video so people would understand you better, overall you did a great job!

Carlor 8-14 said...

Good job! I really like your explanation of your answer and solution, it really make sense! Maybe you can add some video or image next time. Overall, you did a great job!

hendrix817 said...

Good job I like how you changed the colors you might want to put a video next time